The bispectrum is the leading non-Gaussian statistic in large scale structure clustering and encodes the interactions in the underlying field. It is thus an important diagnostic for primordial non-Gaussianity and higher order galaxy biasing. In this paper we present a detailed test and calibration of the matter bispectrum counterterms in the effective field theory of large scale structure against a suite of $N$-body simulations. We are going beyond previous studies in employing realization-based perturbation theory that allows for a significant reduction in cosmic variance error bars. This enables the measurement of the low-energy constants on large scales before two-loop corrections become relevant, around $k<0.09h{\mathrm{Mpc}}^{-1}$ at $z=0$. We also go beyond previous work in using bispectrum propagator terms, i.e., correlators with linear and second order fields, to quantify the two new counterterms in isolation and to establish consistency with the power spectrum counterterm. By investigating the fully nonlinear bispectrum, $B_{\mathrm{nnn}}$, as well as the terms $B_{\mathrm{n}11}$ and $B_{\mathrm{n}21}$, we find evidence for the new counterterms deviating from the shape suggested by the UV limit of the relevant bispectrum contributions. We also show that the commonly used Einstein–de Sitter approximation for the time dependence of the tree-level bispectrum is insufficient for precise studies of the one-loop bispectrum and that it is necessary to use $\mathrm{\Lambda }\mathrm{CDM}$ growth factors in order to obtain meaningful one-loop counterterm constraints. Finally, we also find evidence for small deviations in the growth factors that arise from time integration inaccuracies in the $N$-body simulations.

We present the new parton distribution functions (PDFs) from the CTEQ-TEA collaboration, obtained using a wide variety of high-precision Large Hadron Collider (LHC) data, in addition to the combined HERA $\mathrm{I}+\text{II}$ deep-inelastic scattering dataset, along with the datasets present in the CT14 global QCD analysis. New LHC measurements in single-inclusive jet production with the full rapidity coverage, as well as production of Drell-Yan pairs, top-quark pairs, and high-$p_T$ $Z$ bosons, are included to achieve the greatest sensitivity to the PDFs. The parton distributions are determined at next-to-leading order and next-to-next-to-leading order, with each of these PDFs accompanied by error sets determined using the Hessian method. Fast PDF survey techniques, based on the Hessian representation and the Lagrange multiplier method, are used to quantify the preference of each data set to quantities such as ${\alpha }_s(m_Z)$, and the gluon and strange quark distributions. We designate the main resulting PDF set as CT18. The ATLAS 7 TeV precision $W/Z$ data are not included in CT18, due to their tension with other datasets in the global fit. Alternate PDF sets are generated including the ATLAS precision 7 TeV $W/Z$ data (CT18A), a new scale choice for low-$x$ DIS data (CT18X), or all of the above with a slightly higher choice for the charm mass (CT18Z). Theoretical calculations of standard candle cross sections at the LHC (such as the $gg$ fusion Higgs boson cross section) are presented.

Efforts to detect a primordial $B$-mode of cosmic microwave background polarization generated by inflationary gravitational waves ought to mitigate the large variance associated with the $B$-modes produced by gravitational lensing, a process known as delensing. A popular approach to delensing entails building a lensing $B$-mode template by mimicking the lensing operation, either at gradient order or nonperturbatively, using high-resolution $E$-mode observations and some proxy of the lensing potential. By explicitly calculating all contributions to two-loop order in lensing to the power spectrum of $B$-modes delensed with such a template in the noise-free limit, we are able to show that: (i) corrections to the leading-order calculation of the lensing $B$-mode power spectrum only enter at the $O(1)\%$ level because of extensive cancellations between large terms at next-to-leading order; (ii) these cancellations would disappear if a gradient-order template were to be built from unlensed or delensed $E$-modes, giving rise to a residual delensing floor of $O(10)\%$ of the original power; (iii) new cancellations arise when the lensed $E$-modes are used in the gradient-order template, allowing for the delensing floor to be as low as $O(1)\%$ of the original power in practical applications of this method; and (iv) these new cancellations would disappear for a nonperturbative template constructed from the lensed $E$-modes, reintroducing a residual delensing floor of $O(10)\%$. We further show that the gradient-order template outperforms the nonperturbative one in realistic scenarios with noisy estimates of the $E$-mode polarization and lensing potential. We, therefore, recommend that in practical applications of $B$-mode template delensing, where the template is constructed directly from the (filtered) observed $E$-modes, the gradient-order approach should be used rather than a nonperturbative remapping.

The search for primordial gravitational waves in the cosmic microwave background (CMB) will soon be limited by our ability to remove the lensing contamination to $B$-mode polarization. The often-used quadratic estimator for lensing is known to be suboptimal for surveys that are currently operating and will continue to become less and less efficient as instrumental noise decreases. While foregrounds can, in principle, be mitigated by observing in more frequency bands, progress in delensing hinges entirely on algorithmic advances. We demonstrate here a new inference method that solves this problem by sampling the exact Bayesian posterior of any desired cosmological parameters, of the gravitational lensing potential, and of the delensed CMB maps, given lensed temperature and polarization data. We validate the method using simulated CMB data with nonwhite noise and masking on up to $650{\mathrm{deg}}^2$ patches of sky. A unique strength of this approach is the ability to perform joint inference of cosmological parameters, which control both the primordial CMB and the lensing potential, which we demonstrate here for the first time by sampling both the tensor-to-scalar ratio, $r$, and the amplitude of the lensing potential, $A_{\varphi }$. The method allows us to perform the most precise check to-date of several important approximations underlying CMB-S4 $r$ forecasting, and we confirm these yield the correct expected uncertainty on $r$ to better than 10%.

A new technique to search for new scalar and tensor interactions at the submicrometer scale is presented. The technique relies on small shifts of nuclear $\gamma$ lines produced by the coupling between matter and the nuclei in the source or absorber of a Mössbauer spectrometer. Remarkably, such energy shifts are rather insensitive to electromagnetic interactions that represent the largest background in searches for new forces using atomic matter. This is because nuclei are intrinsically shielded by the electron clouds. Additionally, electromagnetic interactions cause energy shifts by coupling to nuclear moments that are suppressed by the size of the nuclei, while new scalar interactions can directly affect these shifts. Finally, averaging over unpolarized nuclei, further reduces electromagnetic interactions. We discuss several possible configurations, using the traditional Mössbauer effect as well as nuclear resonant absorption driven by synchrotron radiation. For this purpose, we examine the viability of well-known Mössbauer nuclides along with more exotic ones that result in substantially narrower resonances. We find that the technique introduced here could substantially improve the sensitivity to a variety of new interactions and could also be used, in conjunction with mechanical force measurements, to corroborate a discovery or explore the new physics that may be behind a discovery.

Gravitational waves (GW), as light, are gravitationally lensed by intervening matter, deflecting their trajectories, delaying their arrival and occasionally producing multiple images. In theories beyond general relativity, new gravitational degrees of freedom add an extra layer of complexity and richness to GW lensing. We develop a formalism to compute GW propagation beyond general relativity over general space-times, including kinetic interactions with new fields. Our framework relies on identifying the dynamical propagation eigenstates (linear combinations of the metric and additional fields) at leading order in a short-wave expansion. We determine these eigenstates and the conditions under which they acquire a different propagation speed around a lens. Differences in speed between eigenstates cause birefringence phenomena, including time delays between the metric polarizations (orthogonal superpositions of $h_{+}$, $h_{\times }$) observable without an electromagnetic counterpart. In particular, GW echoes are produced when the accumulated delay is larger than the signal’s duration, while shorter time delays produce a scrambling of the waveform. We also describe the formation of GW shadows as nonpropagating metric components are sourced by the background of the additional fields around the lens. As an example, we apply our methodology to quartic Horndeski theories with Vainshtein screening and show that birefringence effects probe a region of the parameter space complementary to the constraints from the multimessenger event GW170817. In the future, identified strongly lensed GWs and binary black holes merging near dense environments, such as active galactic nuclei, will fulfill the potential of these novel tests of gravity.

We demonstrate the power of the black hole mass gap as a novel probe of fundamental physics. New light particles that couple to the Standard Model can act as an additional source of energy loss in the cores of population-III stars, dramatically altering their evolution. We investigate the effects of two paradigmatic weakly coupled, low-mass particles, axions and hidden photons, and find that the pulsational pair instability, which causes a substantial amount of mass loss, is suppressed. As a result, it is possible to form black holes of $72{\mathrm{M}}_{\odot }$ or heavier, deep inside the black hole mass gap predicted by the Standard Model. The upper edge of the mass gap is raised to $>130{\mathrm{M}}_{\odot }$, implying that heavier black holes, anticipated to be observed after LIGO’s sensitivity is upgraded, would also be impacted. In contrast, thermally produced heavy particles would remain in the core, leading to the tantalizing possibility that they drive a new instability akin to the electron-positron pair instability. We investigate this effect analytically and find that stars that avoid the electron-positron pair instability could experience this new instability. We discuss our results in light of current and upcoming gravitational wave interferometer detections of binary black hole mergers.

The Migdal effect in a dark-matter-nucleus scattering extends the direct search experiments to the sub-GeV mass region through electron ionization with sub-keV detection thresholds. In this paper, we derive a rigorous and model-independent “Migdal-photoabsorption” relation that links the sub-keV Migdal process to photoabsorption. This relation is free of theoretical uncertainties as it only requires the photoabsorption cross section as the experimental input. Validity of this relation is explicitly checked in the case of xenon with a state-of-the-art atomic calculation that is well benchmarked by experiments. The predictions based on this relation for xenon, argon, semiconductor silicon, and germanium detectors are presented and discussed.

Results are reported from an amplitude analysis of the $B^{+}\to D^{+}{D}^{-}{K}^{+}$ decay. The analysis is carried out using LHCb proton-proton collision data taken at $\sqrt{s}=7$, 8, and 13 TeV, corresponding to a total integrated luminosity of $9{\mathrm{fb}}^{-1}$. In order to obtain a good description of the data, it is found to be necessary to include new spin-0 and spin-1 resonances in the $D^{-}{K}^{+}$ channel with masses around $2.9\mathrm{GeV}/c^2$, and a new spin-0 charmonium resonance in proximity to the spin-2 ${\chi }_{c2}(3930)$ state.

We compute the covariance of the galaxy power spectrum multipoles in perturbation theory, including the effects of nonlinear evolution, nonlinear and nonlocal bias, radial redshift-space distortions, arbitrary survey window, and shot noise. We rewrite the power spectrum FKP estimator in terms of the usual windowed galaxy fluctuations and the fluctuations in the number of galaxies inside the survey volume. We show that this leads to a stronger supersample covariance than assumed in the literature and causes a substantial leakage of Gaussian information. We decompose the covariance matrix into several contributions that provide an insight into its behavior for different biased tracers. We show that for realistic surveys, the covariance of power spectrum multipoles is already dominated by shot noise and super survey mode coupling in the weakly nonlinear regime. Both these effects can be accurately modeled analytically, making a perturbative treatment of the covariance very compelling. Our method allows for the covariance to be varied as a function of cosmology and bias parameters very efficiently, with survey geometry entering as fixed kernels that can be computed separately using fast fourier transforms (FFTs). We find excellent agreement between our analytic covariance and that estimated from BOSS DR12 Patchy mock catalogs in the whole range we tested, up to $k=0.6\mathrm{h}/\mathrm{Mpc}$. This bodes well for application to future surveys such as DESI and Euclid.

We propose a codimension-two holography between a gravitational theory on a $d+1$ dimensional wedge spacetime and a $d-1$ dimensional CFT which lives on the corner of the wedge. Formulating this as a generalization of $\mathrm{AdS}/\mathrm{CFT}$, we explain how to compute the free energy, entanglement entropy and correlation functions of the dual CFTs from gravity. In this wedge holography, the holographic entanglement entropy is computed by a double minimization procedure. Especially, for a four dimensional gravity ($d=3$), we obtain a two dimensional CFT and the holographic entanglement entropy perfectly reproduces the known result expected from the holographic conformal anomaly. We also discuss a lower dimensional example ($d=2$) and find that a universal quantity naturally arises from gravity, which is analogous to the boundary entropy. Moreover, we consider a gravity on a wedge region in Lorentzian AdS, which is expected to be dual to a CFT with a spacelike boundary. We formulate this new holography and compute the holographic entanglement entropy via a Wick rotation of the AdS/BCFT construction. Via a conformal map, this wedge spacetime is mapped into a geometry where a bubble-of-nothing expands under time evolution. We reproduce the holographic entanglement entropy for this gravity dual via CFT calculations.

In this work, we present the first-ever calculation of the isovector flavor combination of the twist-3 parton distribution function $g_T(x)$ for the proton from lattice quantum chromodynamics (QCD). We use an ensemble of gauge configurations with two degenerate light, a strange, and a charm quarks ($N_f=2+1+1$) of maximally twisted mass fermions with a clover improvement. The lattice has a spatial extent of 3 fm and lattice spacing of 0.093 fm and reproduces a pion mass of 260 MeV. We use the quasidistribution approach and employ three values of the proton momentum boost, 0.83, 1.25, and 1.67 GeV. We use a source-sink separation of 1.12 fm to suppress excited-states contamination. The lattice data are renormalized nonperturbatively. We calculate the matching equation within Large Momentum Effective Theory, which is applied to the lattice data in order to obtain $g_T$. The final distribution is presented in the $\overline{\mathrm{MS}}$ scheme at a scale of 2 GeV. We also calculate the helicity distribution $g_1$ to test the Wandzura-Wilczek approximation for $g_T$. We find that the approximation works well for a broad range of $x$. This work demonstrates the feasibility of accessing twist-3 parton distribution functions from novel methods within lattice QCD and can provide essential insights into the structure of hadrons.

We study nonlinear trident in laser pulses in the high-energy limit, where the initial electron experiences, in its rest frame, an electromagnetic field strength above Schwinger’s critical field. At lower energies the dominant contribution comes from the “two-step” part, but in the high-energy limit the dominant contribution comes instead from the one-step term. We obtain new approximations that explain the relation between the high-energy limit of trident and pair production by a Coulomb field, as well as the role of the Weizsäcker-Williams approximation and why it does not agree with the high-$\chi$ limit of the locally-constant-field approximation. We also show that the next-to-leading order in the large-$a_0$ expansion is, in the high-energy limit, nonlocal and is numerically very important even for quite large $a_0$. We show that the small-$a_0$ perturbation series has a finite radius of convergence, but using Padé-conformal methods we obtain resummations that go beyond the radius of convergence and have a large numerical overlap with the large-$a_0$ approximation. We use Borel-Padé-conformal methods to resum the small-$\chi$ expansion and obtain a high precision up to very large $\chi$. We also use newer resummation methods based on hypergeometric/Meijer-G and confluent hypergeometric functions.

We introduce wavelet phase harmonics (WPH) statistics: interpretable low-dimensional statistics that describe 2D non-Gaussian fields. These statistics are built from WPH moments, which were recently introduced in the data science and machine learning community. We apply WPH statistics to projected 2D matter density fields from the Quijote $N$-body simulations of the large-scale structure of the Universe. By computing Fisher information matrices, we find that the WPH statistics place more stringent constraints on four of five cosmological parameters when compared to statistics based on the combination of the power spectrum and bispectrum. We also use the WPH statistics with a maximum entropy model to statistically generate new 2D density fields that accurately reproduce the probability density function, the mean and standard deviation of the power spectrum, the bispectrum, and Minkowski functionals of the input density fields. Although other methods are efficient for either parameter estimates or statistical syntheses of the large-scale structure, WPH statistics are the first statistics that achieve state-of-the-art results for both tasks as well as being interpretable.

We adopt a two-moment formalism, together with a reference-metric approach, to express the equations of relativistic radiation hydrodynamics in a form that is well suited for numerical implementations in curvilinear coordinates. We illustrate the approach by employing a gray opacity in an optically thick medium. As numerical demonstrations we present results for two test problems, namely stationary, slab-symmetric solutions in flat spacetimes, including shocks, and heated Oppenheimer-Snyder collapse to a black hole. For the latter, we carefully analyze the transition from an initial transient to a post-transient phase that is well described by an analytically known diffusion solution. We discuss the properties of the numerical solution when rendered in moving-puncture coordinates.

We calculate finite-$N_{\mathrm{c}}$ corrections to the next-to-leading order (NLO) Balitsky-Kovchegov (BK) equation. We find analytical expressions for the necessary correlators of six Wilson lines in terms of the two-point function using the Gaussian approximation. In a suitable basis, the problem reduces from the diagonalization of a six-by-six matrix to the diagonalization of a three-by-three matrix, which can easily be done analytically. We study numerically the effects of these finite-$N_{\mathrm{c}}$ corrections on the NLO BK equation. In general, we find that the finite-$N_{\mathrm{c}}$ corrections are smaller than the expected $1/N_{\mathrm{c}}^2\sim 10\%$. The corrections may be large for individual correlators, but have less of an influence on the shape of the amplitude as a function of the dipole size. They have an even smaller effect on the evolution speed as a function of rapidity.

We report results from searches for new physics with low-energy electronic recoil data recorded with the XENON1T detector. With an exposure of 0.65 tonne-years and an unprecedentedly low background rate of $76\pm 2_{\mathrm{stat}}\mathrm{events}/(\mathrm{tonne}\times \mathrm{year}\times \mathrm{keV})$ between 1 and 30 keV, the data enable one of the most sensitive searches for solar axions, an enhanced neutrino magnetic moment using solar neutrinos, and bosonic dark matter. An excess over known backgrounds is observed at low energies and most prominent between 2 and 3 keV. The solar axion model has a $3.4\sigma$ significance, and a three-dimensional 90% confidence surface is reported for axion couplings to electrons, photons, and nucleons. This surface is inscribed in the cuboid defined by $g_{\mathrm{ae}}<3.8\times {10}^{-12}$, $g_{\mathrm{ae}}{g}_{\mathrm{an}}^{\mathrm{eff}}<4.8\times {10}^{-18}$, and $g_{\mathrm{ae}}{g}_{\mathrm{a}\mathrm{\gamma }}<7.7\times {10}^{-22}{\mathrm{GeV}}^{-1}$, and excludes either $g_{\mathrm{ae}}=0$ or $g_{\mathrm{ae}}{g}_{\mathrm{a}\mathrm{\gamma }}=g_{\mathrm{ae}}{g}_{\mathrm{an}}^{\mathrm{eff}}=0$. The neutrino magnetic moment signal is similarly favored over background at $3.2\sigma$, and a confidence interval of ${\mu }_{\nu }\in (1.4,2.9)\times {10}^{-11}{\mu }_B$ (90% C.L.) is reported. Both results are in strong tension with stellar constraints. The excess can also be explained by $\beta$ decays of tritium at $3.2\sigma$ significance with a corresponding tritium concentration in xenon of $(6.2\pm 2.0)\times {10}^{-25}\mathrm{mol}/\mathrm{mol}$. Such a trace amount can neither be confirmed nor excluded with current knowledge of its production and reduction mechanisms. The significances of the solar axion and neutrino magnetic moment hypotheses are decreased to $2.0\sigma$ and $0.9\sigma$, respectively, if an unconstrained tritium component is included in the fitting. With respect to bosonic dark matter, the excess favors a monoenergetic peak at $(2.3\pm 0.2)\mathrm{keV}$ (68% C.L.) with a $3.0\sigma$ global ($4.0\sigma$ local) significance over background. This analysis sets the most restrictive direct constraints to date on pseudoscalar and vector bosonic dark matter for most masses between 1 and $210\mathrm{keV}/{\mathrm{c}}^2$. We also consider the possibility that ${}^{37}\mathrm{Ar}$ may be present in the detector, yielding a 2.82 keV peak from electron capture. Contrary to tritium, the ${}^{37}\mathrm{Ar}$ concentration can be tightly constrained and is found to be negligible.

Primordial black holes (PBH), produced through a variety of processes in the early universe, could fill galactic halos accounting for a fraction or the totality of the dark matter. In particular, PBH with substellar masses could be captured by stars, start to swallow their material, and eventually turn them into BH, hence originating a peculiar new type of stellar catastrophic event. Here we revisit this process in the most favorable case of PBH capture by neutron stars. We detail a number of novel features in the capture phase, during the settling within the star and mass growth of the PBH, and illustrate some phenomenological consequences. In particular, we point out that in the subsonic regime the PBH drag takes the form of a Bondi accretion. As a result, the onset of the final transmutation of the NS into a stellar sized BH is expected with the PBH seed in slight off-center position. We also compute the gravitational wave energy-loss and signals associated to different phases of the PBH-stellar interaction. In particular, the emission associated to the accretion phase is periodic with a few kHz frequency; in the rare case of a nearby Galactic event and for light PBH, it could constitute a warning of the forthcoming transmutation.

We present a search for anisotropic cosmic birefringence in $500{\mathrm{deg}}^2$ of southern sky observed at 150 GHz with the SPTpol camera on the South Pole Telescope. We reconstruct a map of cosmic polarization rotation anisotropies using higher-order correlations between the observed cosmic microwave background (CMB) $E$ and $B$ fields. We then measure the angular power spectrum of this map, which is found to be consistent with zero. The nondetection is translated into an upper limit on the amplitude of the scale-invariant cosmic rotation power spectrum, $L(L+1)C_L^{\alpha \alpha }/2\pi <0.10\times {10}^{-4}{\mathrm{rad}}^2$ ($0.033{\mathrm{deg}}^2$, 95% C.L.). This upper limit can be used to place constraints on the strength of primordial magnetic fields, $B_{1\mathrm{Mpc}}<17\mathrm{nG}$ (95% C.L.), and on the coupling constant of the Chern-Simons electromagnetic term $g_{a\gamma }<4.0\times {10}^{-2}/H_I$ (95% C.L.), where $H_I$ is the inflationary Hubble scale. For the first time, we also cross-correlate the CMB temperature fluctuations with the reconstructed rotation angle map, a signal expected to be nonvanishing in certain theoretical scenarios, and find no detectable signal. We perform a suite of systematics and consistency checks and find no evidence for contamination.

We report in detail on searches for eV-scale sterile neutrinos, in the context of a $3+1$ model, using eight years of data from the IceCube Neutrino Telescope. By analyzing the reconstructed energies and zenith angles of 305,735 atmospheric ${\nu }_{\mu }$ and ${\overline{\nu }}_{\mu }$ events we construct confidence intervals in two analysis spaces: ${\sin }^2(2{\theta }_{24})$ vs $\mathrm{\Delta }{m}_{41}^2$ under the conservative assumption ${\theta }_{34}=0$; and ${\sin }^2(2{\theta }_{24})$ vs ${\sin }^2(2{\theta }_{34})$ given sufficiently large $\mathrm{\Delta }{m}_{41}^2$ that fast oscillation features are unresolvable. Detailed discussions of the event selection, systematic uncertainties, and fitting procedures are presented. No strong evidence for sterile neutrinos is found, and the best-fit likelihood is consistent with the no sterile neutrino hypothesis with a $p$ value of 8% in the first analysis space and 19% in the second.